This invention relates to mountings for attaching work implements to a vehicle, and more particularly, to a quick attach mounting assembly for releasably connecting work implements such as buckets, snow plows, grapples and the like to the front of an articulated loader.
Conventional front end loaders are generally wheeled or tracked vehicles having a work implement mounted on the outer end of a boom which extends from the front of the machine. A hydraulic hoist cylinder is generally used to raise and lower the boom and work implement. Pivoting of the work implement may be provided by a tilt mechanism which generally includes a linkage actuated by a hydraulic tilt cylinder. Front end loaders of this type are versatile machines which may be used for various job applications with numerous work implements. This versatility has led to the need for a quick attach mounting assembly for readily connecting and disconnecting the various work implements to the loader.
The prior art has provided various forms of attachment mechanisms for such vehicles. One form of an attachment generally employs a hook arrangement whereby a member on the back of a work implement is brought into hooking engagement with a complementary member secured to the boom of the vehicle. Once initial engagement of the hook arrangement occurs, the implement may be raised or tilted to align openings in a pinning arrangement at its other end. A pin is then manually inserted through the aligned openings to secure the implement to the vehicle. Examples of such arrangements are disclosed in U.S. Pat. No. 3,767,075 issued to Leverenz for a "Bucket Loader," and U.S. Pat. No. 3,417,886 issued to Stuart for an "Implement Hitch for Tractors and Loaders." This type of attachment, however, generally requires precise alignment to close tolerances of the openings in the pinning arrangement in order to manually pin and secure the work implement. These attachments may thus require considerable amount of time to properly align the pinning arrangement before securing various work implements, especially if several changes a day are necessary.
Another type of attachment is shown in U.S. Pat. No. 3,760,883 issued to Birk entitled "Quick Hitch Assembly," and U.S. Pat. No. 3,243,066 issued to Gardner entitled "Quick Change Means for Loader Attachments." These attachments generally employ a hook arrangement similar to those previously discussed along with hydraulic cylinders which are actuated to insert and retract pins through aligned openings in a pinning arrangement. This type of attachment, however, also requires precise alignment of the openings in the pinning arrangement. Further, damage to the hydraulic cylinder or pins may result if the hydraulic cylinder is actuated and the pinning arrangement is misaligned.
Still another type of attachment assembly is shown in U.S. Pat. No. 3,935,953 issued to Stedman entitled "Implement Mounting Means for Earthworking Vehicles." This arrangement comprises over-center toggle mechanisms which engage hook members mounted on the back of work implements. The arrangement includes hydraulic locking mechanisms on the boom which must be aligned with openings in the toggle mechanisms prior to connecting or disconnecting the work implements. Precise and proper alignment of locking and toggle mechanisms of this type requires considerable time, and if misaligned, damage to the locking mechanisms can occur.
Unlike the prior art, a quick attach mounting assembly for loader implements in accordance with the present invention employs an arrangement which readily permits connecting and disconnecting work implements without employing hydraulic cylinders and without the necessity of aligning openings in pinning arrangements.